I was a Magmar and an Electabuzz away from 151 Pokemon in Blue version.
100% Megaman X. Um... Link to the Past, Ocarina of Time, Majora's Mask, Windwaker.
Super Mario World, Turtles in Time. PoP SoT/WW
BioShock 2 I beat both stories and upgraded a lot. Achievements are lame though so I ignore their existence.
Sonic Adventure 2 BATTLE on the Gamecube... I was really close, i think 7 or 8 emblems away from flawless and unlocking Green Hill Zone. Then I lost my memory card. XP
I haven't 100%'ed Dragon Age Origins but I have a lot of DLC and Awakening completed, I've also gone through the game 3 times now So I vote that counts.
I Beat every song in GH2 on expert, not 5 stars though... I beat Jordan, do I really need 5 stars for it to count?
I beat every guitar song on RB 1/2 and a lot of dlc, again not 5 stars but whatever...
I don't know, I've completed a lot more games but 100% isn't my idea of a game in most cases, though I'm sure I have 100% others back when games were complete because you finished them.
Soooo... 15+ probably.
Edit: Pokemon Snap!